African queen

[PGFISHER]

Water turned to steam expands to 1600-1700 times its volume. Does this mean that one pound of water will exert 1600 pounds of pressure on a piston?

 

[DianneB]

Re: African queen

No. As water is heated in a closed container, both temperature and pressure increase as heat is continually applied.

The force exerted on the piston of a steam engine is purely the product of pressure times the area of the piston.

 

[PGFISHER]

Re: African queen

If you increas the volume by 1600, would you not also increase the pressure by 1600?

 

[PGFISHER]

Re: African queen

If you increase the volume by 1600, would you not also have 1600 times the pressure to apply?

 

[j_martin]

Re: African queen

If you increase the volume by 1600, would you not also have 1600 times the pressure to apply?

You are confusing terms. A pound (mass) of water, volume converted to a gas (x 1600, I'll take your word for it) and pressure, ie lbs/sq inch.

Add in some other dynamics, like the conversion occurs at different temperatures depending on pressure, and you soon realize why most engineers dealing with phase change thermodynamics are bald.

 

[JustJason]

Re: African queen

With only 13 posts why on earth are you asking about P/V in a boating forum??

 

[JB]

Re: African queen

You left out an important fact.

The 1:1600 estimate works only at 0 change in pressure.

You are light years short of predicting pressure at less than 1600X volume.

 

[Tim Frank]

Re: African queen

If you increas the volume by 1600, would you not also increase the pressure by 1600?

No.... there is an inverse relationship between P & V.

 

[bruceb58]

Re: African queen

Once water becomes a gas you can use IDEAL GAS LAW. Look it up on Google.

PV=NRT

P= pressure
V= volume
N= number of moles(for you guys who took chemistry)
R= Boltzmann's constant
T= temperature(degrees kelvin)

It's Simple!

 

[WizeOne]

Re: African queen

Once water becomes a gas you can use IDEAL GAS LAW. Look it up on Google.

PV=NRT

P= pressure
V= volume
N= number of moles(for you guys who took chemistry)
R= Boltzmann's constant
T= temperature(degrees kelvin)

It's Simple!

Ok, can I go back to my Cheerios now?

 

[Tim Frank]

Re: African queen

Once water becomes a gas you can use IDEAL GAS LAW. Look it up on Google.

PV=NRT

P= pressure
V= volume
N= number of moles(for you guys who took chemistry)
R= Boltzmann's constant
T= temperature(degrees kelvin)

It's Simple!

Unfortunately I don't need to google it, I can still remember...we affectionately (?) referred to our teacher as the "Chem Nazi" and we drilled a bit too much
At my age the hard disc is starting to get full, and I'd rather not remember this and so have room for a few extra boating repair tips...

Anyway, not that it matters, but in memory of the Chem Nazi , in this equation (PV=nRT ) n= number of moles, by convention N is Avogadro's constanr...and R is the "Gas constant" and is, numerically, (units are too complicated to type out)... ~ 0.082....Boltzmann's constant typically is referred to as "k", is used in other applications, and has a numeric value of ~ 1.38 x 10 **(-16)

Since I've finished picking the fly p**p out of the pepper, NOW Wizeone can go back to his Cheerios....

 

[PGFISHER]

Re: African queen

I'm thinking that JUSTJASON has never seen the movie African Queen!

 

[BWR1953]

Re: African queen

I'm thinking that JUSTJASON has never seen the movie African Queen!

Yup.

 

[bruceb58]

Re: African queen

Anyway, not that it matters, but in memory of the Chem Nazi , in this equation (PV=nRT ) n= number of moles, by convention N is Avogadro's constanr...

Sorry..meant little "n"..which is moles.

 

[Tim Frank]

Re: African queen

Sorry..

You must have missed the part of my post "not that it matters..."...It doesn't....

 

[Tig]

Re: African queen

Sorry..meant little "n"..which is moles.

OK, that's better. I though I was going to have to nail ya on that one.

 

[PGFISHER]

Re: African queen

It seems that I asked the wrong question. I understand that P is inversely related to V. If I have a closed vessel with water at atmosphere and raise the temperature to 212 degrees, the water should want to occupy 1600 times the volume but can't. Does the pressure rise to 1600 times atmosphere (about 28,000 psi) ? I assume, this is what makes a can of beer explode in a campfire, As mythbusters says "don't try this; EVER"!

 

[PGFISHER]

Re: African queen

Unless you actually want a shower of hot sparks raining down in a 100 foot circle!

 

[CN Spots]

Re: African queen

U stop math speek! Make hed hurt!

 

[Bob_VT]

Re: African queen

U stop math speek! Make hed hurt!

LOL Okay..... if you have a six-pack and drink them all what do you have left?

The answer is a a trip to the store for another six pack